CN114277386A

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Info

Publication number: CN114277386A
Application number: CN202110901086.5A
Authority: CN
Inventors: 郑南峰; 胡程奕; 陶华冰; 陶勇冰; 游文韬
Original assignee: Tan Kah Kee Innovation Laboratory
Current assignee: Tan Kah Kee Innovation Laboratory
Priority date: 2021-08-06
Filing date: 2021-08-06
Publication date: 2022-04-05
Also published as: WO2023011520A1

Abstract

Translated fromChinese

本发明提供一种电化学还原四氯化锡的方法及反应装置。电化学反应装置包括：阳极组件，阳极组件包括第一电极，第一电极被配置为与待氧化物接触；阴极组件，阴极组件包括第二电极，第二电极被配置为与待还原物接触；质子交换膜，质子交换膜设置在阴极组件和阳极组件之间；电源，电源被配置为在阳极组件和阴极组件之间施加正电压。

The invention provides a method and a reaction device for electrochemically reducing tin tetrachloride. The electrochemical reaction device includes: an anode assembly, the anode assembly includes a first electrode, the first electrode is configured to be in contact with the to-be-oxidized substance; the cathode assembly, the cathode assembly includes a second electrode, and the second electrode is configured to be in contact with the to-be-reduced substance; The proton exchange membrane, the proton exchange membrane is disposed between the cathode assembly and the anode assembly; the power source, the power source is configured to apply a positive voltage between the anode assembly and the cathode assembly.

Description

Method and reaction device for electrochemically reducing stannic chloride

Technical Field

The invention belongs to the field of electrochemical engineering, and particularly relates to a method and a reaction device for electrochemically reducing stannic chloride.

Background

The phenylhydrazine compound is an important organic synthesis intermediate and is widely applied to the fields of dyes, pesticides, medicines and the like. At present, the classical synthetic route of phenylhydrazine and its derivatives is as follows:

aniline and sodium nitrite are subjected to diazotization reaction to generate diazonium salt, and the diazonium salt is reduced into phenylhydrazine hydrochloride by using a reducing agent such as tin dichloride or sodium sulfite under an acidic condition. The stannous chloride reduced diazonium salt has higher selectivity and yield and is widely used in industry. However, tin dichloride is oxidized into tin tetrachloride while reducing diazonium salt, and a large amount of tin tetrachloride exists in waste liquid after reaction, thereby causing serious environmental pollution.

The reduction of the stannic chloride into the stannic chloride can reduce the production cost and realize the recycling of the stannic salt. The current method for reducing stannic chloride mainly comprises the following steps:

some related art uses a method of reducing tin tetrachloride with aluminum particles, but this method also generates aluminum trichloride while reducing tin tetrachloride, causing secondary pollution.

Some related art methods of reducing tin tetrachloride using metallic tin consume a large amount of metallic tin, rapidly increase the concentration of tin in a solution, and are difficult to recycle many times. In addition, the metallic tin contains other impurity metallic elements, and subsequent separation and purification are needed, so that the production cost is increased.

Some related art processes use hydrogen as a reducing agent to reduce tin tetrachloride to tin dichloride under noble metal catalysis. The process method is green and environment-friendly, but needs to be carried out under the conditions of high temperature and high pressure, and the chemical reaction device has higher manufacturing cost.

Some of the related arts use a method of electroreduction of tin tetrachloride using a diaphragm-free electrolytic cell, but this method uses metallic nickel as a cathode, which is gradually dissolved by reaction with hydrochloric acid, and has poor stability, while the generated nickel chloride enters the reaction solution to cause contamination. In addition, tin dichloride generated by cathode reduction in the diaphragm-free electrolytic cell gradually diffuses to the anode and is re-oxidized into tin tetrachloride, so that the reaction current efficiency is greatly reduced, and the energy consumption is increased.

Disclosure of Invention

The present disclosure provides an electrochemical reaction apparatus having a proton exchange membrane for performing an electrochemical reaction, capable of preventing a reduced product (e.g., tin dichloride) from migrating to an anode for oxidation.

In some aspects, the present disclosure provides an electrochemical reaction device comprising,

an anode assembly comprising a first electrode configured to be in contact with an oxide to be oxidized;

a cathode assembly including a second electrode configured to be in contact with the object to be reduced;

the proton exchange membrane is arranged between the cathode assembly and the anode assembly;

a power supply configured to apply a positive voltage between the anode assembly and the cathode assembly.

In some embodiments, the oxide comprises: h₂O，H₂Or a combination thereof.

In some embodiments, the species to be reduced includes: solutions containing metal cations (e.g. containing Sn)⁴⁺The solution of (a).

In some embodiments, the anode assembly further comprises an oxidation catalyst configured to be in contact with the oxide.

In some embodiments, the oxidation catalyst is selected from a Hydrogen Oxidation Reaction (HOR) catalyst, an Oxygen Evolution Reaction (OER) catalyst, or a combination thereof.

In some embodiments, the oxygen evolution reaction catalyst (OER) is a catalyst material capable of catalyzing an oxygen evolution reaction.

In some embodiments, the hydro-oxidation reaction (HOR) catalyst is a catalyst material capable of catalyzing a hydro-oxidation reaction.

In some embodiments, a hydro-oxidation reaction (HOR) catalyst comprises: a platinum group element.

In some embodiments, an Oxygen Evolution Reaction (OER) catalyst comprises: ruthenium, iridium, or combinations thereof.

In some embodiments, the first electrode comprises a porous electrode;

in some embodiments, the second electrode comprises a porous electrode.

In some embodiments, the material of the first electrode comprises titanium metal or titanium alloy;

in some embodiments, the material of the second electrode comprises a carbon material (e.g., carbon fiber).

In some embodiments, the second electrode comprises at least one of carbon fiber paper, carbon fiber cloth, carbon fiber felt, and the like.

In some embodiments, the first electrode is a gas diffusion electrode.

In some embodiments, the first electrode is at least one of a titanium mesh, titanium foam, titanium fiber felt, powder sintered porous titanium, and the like.

In some embodiments, the first electrode is loaded with a platinum carbon catalyst and the platinum loading is from 0.1 to 1mg/cm²Preferably 0.5mg/cm²。

In some embodiments, the ruthenium iridium catalyst is supported on the first electrode.

In some embodiments, the anode assembly further comprises a first plate, a surface of the first plate facing the first electrode is provided with flow channels for distributing the oxide to be distributed, and the first electrode is positioned between the first plate and the proton exchange membrane.

In some embodiments, the first plate is a bipolar plate.

In some embodiments, the cathode assembly further comprises a second plate, the surface of the second plate facing the second electrode is provided with flow channels for distributing the substance to be reduced, and the second electrode is positioned between the second plate and the proton exchange membrane.

In some embodiments, the second plate is a bipolar plate.

In some embodiments, the material of the first plate comprises: graphite, titanium or titanium alloy, zirconium or zirconium alloy, tantalum or tantalum alloy, hastelloy, or combinations thereof.

In some embodiments, the material of the second plate comprises: graphite, titanium or titanium alloy, zirconium or zirconium alloy, tantalum or tantalum alloy, hastelloy, or combinations thereof.

In some embodiments, the flow channel is selected from a linear flow channel, a serpentine flow channel, a zig-zag flow channel, a biomimetic vein-shaped flow channel, or a combination thereof.

In some embodiments, a proton exchange membrane comprises: a perfluorosulfonic acid proton exchange membrane, a sulfonated polyetheretherketone proton exchange membrane, a polybenzimidazole proton exchange membrane, or a combination thereof.

In some aspects, the present disclosure provides a method of performing an electrochemical reaction comprising

Providing an electrochemical reaction device as in any one of the above;

providing an anode assembly with a source of oxide;

providing the object to be reduced to the cathode assembly;

a positive voltage is applied between the anode assembly and the cathode assembly, so that the oxide to be reduced is oxidized and the substance to be reduced is reduced.

In some embodiments, the oxide comprises: h₂O，H₂Or a combination thereof;

in some embodiments, the species to be reduced includes: metal cation (e.g. Sn)⁴⁺)。

In some embodiments, the following overall reaction occurs within the electrochemical reaction device:

to an oxide comprising H₂The following reaction occurs at the first electrode: 2H₂→2H⁺+2e^-

The substance to be reduced comprises SnCl₄The following reaction occurs at the second electrode: SnCl₄+2e^-→SnCl₂+2Cl^-。

The following general reaction takes place in the electrochemical reaction apparatus₄+H₂→SnCl₂+2HCl。

In some embodiments, the oxide comprises H₂The anode assembly further comprises a hydrogen oxidation catalyst in contact with the oxide to be oxidized, and the first electrode is a gas diffusion electrode.

In some embodiments, the starting material is SnCl containing 0.5-2 mol/L₄And 1-6 mol/L of HCl aqueous solution, wherein the second electrode is a porous electrode containing carbon fibers. Based on the scheme, the prepared tin dichloride has high purity and high current efficiency, does not have other byproducts, and is environment-friendly.

In some embodiments, the following reactions occur within the electrochemical reaction device:

to an oxide comprising H₂O, the following reaction occurs at the first electrode: 2H₂O→O₂+4H⁺+4e^-；

The substance to be reduced comprises SnCl₄The following reaction occurs at the second electrode: SnCl₄+2e^-→SnCl₂+2Cl^-；

The following overall reaction takes place in the electrochemical reaction apparatus, 2SnCl₄+2H₂O→2SnCl₂+4HCl+O₂。

In some embodiments, the oxide comprises H₂O, the anode assembly further comprises a water oxidation catalyst in contact with the oxide to be oxidized, and the first electrode is a porous electrode containing metal titanium or titanium alloy;

the original substance is SnCl containing 0.5-2 mol/L₄And 1-6 mol/L of HCl aqueous solution, wherein the second electrode is a porous electrode containing carbon fibers.

In some embodiments, the temperature at the first electrode and/or the second electrode is maintained between 25 ℃ and 80 ℃ (e.g., between 40 ℃ and 60 ℃).

In some embodiments, the current density at the first electrode and/or the second electrode is from 100 to 800mA/cm²。

In some embodiments, the method of performing the electrochemical reaction is reducing SnCl₄The method of (1).

In some embodiments, the electrochemical reaction device components are sealed using gaskets or glue, and tightened using bolts and nuts.

In some embodiments, the electrochemical reaction device further comprises a heating temperature control device, a peristaltic pump to control the flow rate of the liquid, and a mass flow meter and back pressure valve to control the flow and pressure of the gas.

The invention has the beneficial effects that:

one or more technical schemes of the present disclosure have one or more of the following advantages:

1) some schemes use an electrochemical reaction device with a proton exchange membrane to prevent migration of reduced products (e.g., reduced metal ions, such as tin dichloride) to anodic oxidation.

2) Some schemes use carbon materials (e.g., carbon fiber paper) as the cathode, effectively suppressing hydrogen evolution reactions in acidic environments.

3) Some schemes use hydrogen or water as a reducing agent, so that the problems of secondary pollution caused by using aluminum as the reducing agent and introduction of impurity metal elements caused by using tin as the reducing agent in the traditional process are solved.

4) The tin dichloride prepared by some schemes has high purity, no other by-products and environmental protection.

5) Some schemes are carried out under the temperature and pressure which are easy to reach industrially, so that the cost of the electrochemical reaction device is reduced, the operation is convenient, and the safety is high;

6) in some schemes, hydrogen or water is introduced into the anode to be used as an oxide, and only 0.6V or 2.0V of voltage is applied to achieve 400mA/cm²The current efficiency of the reaction approaches 100%.

7) The tin tetrachloride reduction method provided by the disclosure has the advantages of high efficiency, energy conservation and environmental protection.

8) The tin tetrachloride reduction method provided by the disclosure is suitable for application in the production of phenylhydrazine compounds, and the method is helpful for reducing the overall production cost and has important industrial application value.

Description of the terms

It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" or "comprising," or "having," when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

Furthermore, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe one element's relationship to another element as illustrated in the figures. It will be understood that the relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one figure is turned over, elements described as being on the "lower" side of other elements would then be oriented on "upper" sides of the other elements. Thus, the exemplary term "lower" can encompass both an orientation of "lower" and "upper," depending on the particular orientation of the figure. Similarly, if the device in one figure is turned over, elements described as "below" or "beneath" other elements would then be oriented "above" the other elements. Thus, the exemplary terms "under" or "beneath" can encompass both an orientation of above and below.

As used herein, "about," "substantially," or "approximately" shall generally mean within 20%, preferably within 10% and more preferably within 5% of a given value or range. Numerical quantities given herein are approximate, meaning that the terms "about", "substantially" or "approximately" can be inferred without expressly stated.

The term "proton exchange membrane" refers to a membrane that is typically made of an ionomer and designed to conduct protons. The proton exchange membrane is selectively permeable to hydrogen ions. The proton exchange membrane may be selected from Nafion115 membrane, Nafion117 membrane, Nafion212 membrane, Nafion211 membrane, or membranes manufactured by Dupont in the united states and having proton conducting capability.

The term "Gas Diffusion Electrode" is understood to mean an Electrode on which three aggregate states, namely a solid state, a liquid state and a gaseous state, come into contact with one another.

Drawings

FIG. 1 is a schematic view of an electrochemical reaction apparatus used in examples 1 and 2.

FIG. 2 is a graph showing the current density of the electrochemical reaction apparatus at different temperatures according to the voltage obtained in example 1.

FIG. 3 is a graph of the rate of formation of tin dichloride at 80 ℃ and the current efficiency as a function of voltage obtained in example 1.

FIG. 4 shows the results of example 1 at 80 ℃ and 400mA/cm²Stability test chart under current density.

FIG. 5 is a graph showing the current density of the electrochemical reaction device as a function of voltage at different temperatures obtained in example 2.

FIG. 6 is a graph of the rate of formation of tin dichloride at 80 ℃ and the current efficiency as a function of voltage obtained in example 2.

FIG. 7 shows the results of example 2 at 80 ℃ and 400mA/cm²Stability test chart under current density.

Detailed Description

Reference will now be made in detail to specific embodiments of the invention. While the invention will be described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the invention to these specific embodiments. On the contrary, these embodiments are intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention.

As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

The reagents, methods and apparatus employed in the present invention are conventional food grade reagents, methods and apparatus in the art, unless otherwise specified. Unless otherwise indicated, the test conditions used in the examples of the present invention are those conventional in the art. The reagents used in the examples of the present invention were all commercially available unless otherwise specified.

Example 1:

fig. 1 shows a schematic view of an electrochemical reaction apparatus of example 1. The electrochemical reaction apparatus includes:

theanode assembly 100, theanode assembly 100 includes afirst electrode 101 and afirst plate 102, a surface of thefirst plate 102 facing thefirst electrode 101 is provided with afirst flow channel 104 for distributing an oxide to be formed, a firstflow channel inlet 151 and a firstflow channel outlet 152, and thefirst electrode 101 is configured to be in contact with the oxide to be formed;

thecathode assembly 200, thecathode assembly 200 includes asecond electrode 201 and a secondpolar plate 202, the surface of the secondpolar plate 202 facing the second electrode is provided with asecond flow channel 106 for distributing the substance to be reduced, a secondflow channel inlet 251 and a secondflow channel outlet 252, thesecond electrode 201 is configured to contact with the substance to be reduced;

aproton exchange membrane 300, theproton exchange membrane 300 being disposed between thecathode assembly 100 and theanode assembly 200; thefirst electrode 101 is positioned between the firstpolar plate 102 and theproton exchange membrane 300; thesecond electrode 201 is positioned between thesecond plate 202 and theproton exchange membrane 300; protons pass through theproton exchange membrane 300 from theanode assembly 100 side into thecathode assembly 200 side in the direction of the arrows;

apower supply 400, thepower supply 400 being configured to apply a positive voltage between theanode assembly 100 and thecathode assembly 200.

In this example, thefirst electrode 101 is a 2 × 2cm gas diffusion electrode (carbon fiber paper with a hydrophobic microporous carbon layer), a Hydrogen Oxidation Reaction (HOR) catalyst (platinum carbon catalyst) is disposed on thefirst electrode 101, thesecond electrode 201 is a 2 × 2cm carbon fiber paper, and theproton exchange membrane 300 is a Nafion212 membrane.

In this embodiment, the oxide is H₂. H is introduced to theanode assembly 100 through the firstflow channel inlet 151₂The hydrogen flowing through thefirst flow channel 104 contacts thefirst electrode 101 and is catalytically oxidized by the voltage, and the insufficiently reacted exhaust gas is discharged through the firstflow channel outlet 152. The hydrogen flow rate was 15mL/min and the aeration pressure was 0.2 bar.

In this example, the substance to be reduced is SnCl₄. The solution to be reduced is SnCl containing 1mol/L₄And 4mol/L HCl in water. The solution to be reduced is introduced into thecathode assembly 200 through the secondflow channel inlet 251, the solution to be reduced flowing through the second flow channel 204 contacts thesecond electrode 201 and is reduced under the action of the voltage, and the reduced solution is discharged through the secondflow channel outlet 252. The flow rate of the solution to be reduced was 50 mL/min.

The following reaction occurs at the first electrode: 2H₂→2H⁺+2e^-

The following reaction occurs at the second electrode: SnCl₄+2e^-→SnCl₂+2Cl^-。

Next, electrochemical reactions 1.1 to 1.2 were carried out by using the electrochemical reaction apparatus of example 1.

Electrochemical reaction 1.1

The temperature of the electrochemical reaction device is kept at room temperature. The electrolysis was carried out for 30 minutes at voltages of 0.2 to 1.0V (interval 0.1V), and the current density was plotted as a function of voltage, taking the stable current density at each voltage. And then, sequentially raising the temperature of the electrochemical reaction device to 40 ℃, 60 ℃ and 80 ℃, and testing the relation of current density with voltage change at different temperatures. FIG. 2 is a graph showing the current densities (mA/cm) of the electrochemical reaction apparatus at different temperatures obtained in example 1²) Graph of the variation with voltage (tank voltage, V). See table below for specific data.

TABLE 1

And (3) taking the solution electrolyzed at different voltages at 80 ℃ in the electrochemical reaction 1.1, determining the concentration of the tin dichloride in the solution by adopting a potassium dichromate chemical titration method, and calculating the generation rate and the current efficiency of the tin dichloride. FIG. 3 shows the rate of formation of tin dichloride (mmol cm) at 80 ℃ obtained in the electrochemical reaction 1.1^-2h^-1) And the current efficiency (%) as a function of voltage (tank voltage, V). See table below for specific data.

TABLE 2

Voltage of	0.4	0.45	0.5	0.55	0.6	0.65	0.7	0.75
									Current efficiency	100	100	99.5	99	98.8	98.4	98.2	98
SnCl₂Generating rates	2.34	3.91	5.16	6.46	7.91	9.44	10.35	9.99

Electrochemical reaction 1.2

Controlling the temperature at the first and second electrodes to 80 deg.C, and applying 400mA/cm between the first and second electrodes²The reaction was terminated at constant current and voltage up to 1V. FIG. 4 shows the results of example 1 at 80 ℃ and 400mA/cm²Stability at current density test chart showing the voltage (cell voltage, V) and current efficiency (%) as a function of time.

TABLE 3

Time/h	0	2	4	6	8	10
							Voltage of	0.58	0.58	0.58	0.58	0.6	0.62
Current efficiency	/	99.5	98.7	98.6	98.2	97.8

Current efficiency (nxe × F)/Q

n: formation of SnCl₄Number of moles (determined by chemical titration)

e: transferring electronic number (e 2)

F: faraday constant (F as 96485)

Q: consumption of electricity (Q ═ I × t)

Example 2:

fig. 1 shows a schematic view of an electrochemical reaction apparatus of example 2. The electrochemical reaction apparatus includes:

aproton exchange membrane 300, theproton exchange membrane 300 being disposed between thecathode assembly 100 and theanode assembly 200; thefirst electrode 101 is positioned between the firstpolar plate 102 and theproton exchange membrane 300; thesecond electrode 201 is positioned between thesecond plate 202 and theproton exchange membrane 300; protons pass through theproton exchange membrane 300 from theanode assembly 100 side to thecathode assembly 200 side in the direction of the arrows.

In this embodiment, thefirst electrode 101 is a 2 × 2cm powder sintered porous titanium electrode, thefirst electrode 101 is provided with an Oxygen Evolution Reaction (OER) catalyst (ruthenium iridium alloy), thesecond electrode 201 is 2 × 2cm carbon fiber paper, and theproton exchange membrane 300 is a Nafion212 membrane.

In this example, the oxide is water (H)₂O). Water is introduced into theanode assembly 100 through the firstflow channel inlet 151, the water flowing through thefirst flow channel 104 contacts thefirst electrode 101 and is catalytically oxidized by the voltage, and gaseous products and insufficiently reacted water are discharged through the firstflow channel outlet 152. The flow rate through the water was 50 mL/min.

In this example, the material to be reduced was tin tetrachloride. The solution to be reduced is SnCl containing 1mol/L₄And 4mol/L HCl in water. The solution to be reduced is introduced into thecathode assembly 200 through the secondflow channel inlet 251, the solution to be reduced flowing through the second flow channel 204 contacts thesecond electrode 201 and is reduced under the action of the voltage, and the reduced solution is discharged through the secondflow channel outlet 252. The flow rate of the solution to be reduced was 50 mL/min.

The following reaction occurs at the first electrode: 2H₂O→O₂+4H⁺+4e^-

The following reaction occurs at the second electrode: SnCl₄+2e^-→SnCl₂+2Cl^-

Next, electrochemical reactions 2.1 to 2.2 were carried out by using the electrochemical reaction apparatus of example 2.

Electrochemical reaction 2.1

The temperature of the electrochemical reaction device is kept at room temperature. The electrolysis was carried out for 30 minutes at a voltage of 1.2 to 2.1V (0.1V interval), and the current density was plotted as a function of voltage, taking the stable current density at each voltage. And then, sequentially raising the temperature of the electrochemical reaction device to 40 ℃, 60 ℃ and 80 ℃, and testing the relation of current density with voltage change at different temperatures. FIG. 5 is a graph showing the current densities (mA/cm) of the electrochemical reaction apparatus at different temperatures obtained in example 2²) Graph of the variation with voltage (tank voltage, V). See table below for specific data.

TABLE 4

And (3) obtaining the solution electrolyzed at different voltages at 80 ℃ in the electrochemical reaction 2.1, determining the concentration of the tin dichloride in the solution by adopting a potassium dichromate chemical titration method, and calculating the generation rate and the current efficiency of the tin dichloride. FIG. 6 is the tin dichloride generation rate (mmol cm) at 80 ℃ obtained in example 2^-2h^-1) And the current efficiency (%) as a function of voltage (tank voltage, V). See table below for specific data.

TABLE 5

Voltage of	1.6	1.7	1.8	1.9	2	2.1
							Current efficiency	99.7	99.8	99	98.6	97.2	77.5
SnCl₂Generating rates	1.15	2.26	4.00	6.30	9.05	9.21

Electrochemical reaction 2.2

Controlling the temperature at the first and second electrodes to 80 deg.C, and applying 400mA/cm between the first andsecond electrodes 0²The reaction was terminated at constant current and the voltage increased to 2.5V. FIG. 7 shows the results of example 2 at 80 ℃ and 400mA/cm²Stability test chart under current density. The graph shows the voltage (tank voltage, V) and current efficiency (%) as a function of time.

TABLE 6

Time/h	0	2	4	6	8	10
							Voltage of	1.99	2.01	2.02	2.04	2.05	2.07
Current efficiency	/	98.8	98.0	97.6	97.4	97

Current efficiency (nxe × F)/Q

n: formation of SnCl₄Number of moles (determined by chemical titration)

e: transferring electronic number (e 2)

F: faraday constant (F as 96485)

Q: consumption of electricity (Q ═ I × t)

According to the experimental results of the implementation 1-2, the electrochemical reaction device disclosed by the invention is utilized, hydrogen or water is introduced into the anode to be used as an oxide to be reduced, the solution containing stannic chloride is introduced into the cathode to be used as a substance to be reduced, and the voltage of 400mA/cm can be achieved only by applying 0.6V or 2.0V²The current efficiency of the reaction approaches 100%. The proton exchange membrane of the electrochemical reaction apparatus effectively prevents the reduced product (e.g., tin dichloride) from migrating to the anode for oxidation. The second electrode of the carbon material effectively suppresses the hydrogen evolution reaction in an acidic environment.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention and not to limit it; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.

Claims

1. An electrochemical reaction device, comprising,

a cathode assembly including a second electrode configured to be in contact with an object to be reduced;

a proton exchange membrane disposed between the cathode assembly and the anode assembly;

a power supply configured to apply a positive voltage between the anode assembly and cathode assembly.

2. The electrochemical reaction device according to claim 1, characterized by any one of the following:

-said oxide to be oxidized comprises: h₂O，H₂Or a combination thereof;

-the material to be reduced comprises: solutions containing metal cations (e.g. containing Sn)⁴⁺The solution of (a).

3. The electrochemical reaction device of claim 1, wherein the anode assembly further comprises an oxidation catalyst configured to be in contact with an oxide to be oxidized;

preferably, the oxidation catalyst is selected from a Hydrogen Oxidation Reaction (HOR) catalyst, an Oxygen Evolution Reaction (OER) catalyst, or a combination thereof;

preferably, the hydro-oxidation reaction (HOR) catalyst comprises: a platinum group element;

preferably, the Oxygen Evolution Reaction (OER) catalyst comprises: ruthenium, iridium, or combinations thereof.

4. The electrochemical reaction device according to claim 1, characterized by any one of the following:

-the first electrode comprises a porous electrode;

-the second electrode comprises a porous electrode.

5. The electrochemical reaction device according to claim 1, characterized by any one of the following:

-the material of the first electrode comprises titanium metal or titanium alloy;

the material of the second electrode comprises a carbon material (e.g. carbon fiber).

6. The electrochemical reaction device according to claim 1, characterized by any one of the following:

the anode assembly further comprises a first plate, the surface of which facing the first electrode is provided with flow channels for distributing the oxides to be oxidized, the first electrode being located between the first plate and the proton exchange membrane;

the cathode assembly further comprises a second plate, the surface of which facing the second electrode is provided with flow channels for distributing the substance to be reduced, the second electrode being located between the second plate and the proton exchange membrane.

7. The electrochemical reaction device according to claim 1, characterized by any one of the following:

the first polar plate is made of the following materials: graphite, titanium or titanium alloy, zirconium or zirconium alloy, tantalum or tantalum alloy, hastelloy, or combinations thereof;

the second polar plate is made of the following materials: graphite, titanium or titanium alloy, zirconium or zirconium alloy, tantalum or tantalum alloy, hastelloy, or combinations thereof.

8. The electrochemical reaction device of claim 1, wherein the flow channel is selected from a linear flow channel, a serpentine flow channel, a # -shaped flow channel, a bionic vein-shaped flow channel, or a combination thereof.

9. The electrochemical reaction device according to claim 1, wherein the proton exchange membrane comprises: a perfluorosulfonic acid proton exchange membrane, a sulfonated polyetheretherketone proton exchange membrane, a polybenzimidazole proton exchange membrane, or a combination thereof.

10. A method of performing an electrochemical reaction comprising

Providing an electrochemical reaction device according to any one of claims 1 to 9;

providing the anode assembly with an oxide to be oxidized;

providing the cathode assembly with a material to be reduced;

and applying positive voltage between the anode assembly and the cathode assembly to oxidize the oxide and reduce the matter to be reduced.

11. The method according to claim 10, characterized by any of the following:

-said oxide to be oxidized comprises: h₂O，H₂Or a combination thereof;

-the material to be reduced comprises: metal cation (e.g. Sn)⁴⁺)。

12. The method of claim 10, wherein,

the oxide to be oxidized comprises H₂At the first electrode, the following reaction occurs: 2H₂→2H⁺+2e^-

13. The method of claim 12, wherein,

the oxide to be oxidized comprises H₂The anode assembly further comprises a hydrogen oxidation catalyst in contact with the oxide to be oxidized, the first electrode being, for example, a gas diffusion electrode;

the to-be-detected substance is SnCl containing 0.5-2 mol/L₄And 1-6 mol/L of HCl aqueous solution, and the second electrode is a porous electrode containing carbon fibers.

14. The method of claim 10, wherein,

the oxide to be oxidized comprises H₂O, the following reaction occurs at the first electrode: 2H₂O→O₂+4H⁺+4e^-

The substance to be reduced comprises SnCl₄The following reaction occurs at the second electrode: SnCl₄+2e^-→SnCl₂+2Cl^-

15. The method of claim 10, wherein,

the oxide to be oxidized comprises H₂O, the anode assembly further comprising a water oxidation catalyst in contact with the oxide to be oxidized, the first electrode being, for example, a metal-containing titanium or titanium alloyThe porous electrode of (4);

16. The method according to claim 10, characterized by any of the following:

the temperature at the first electrode and/or the second electrode is kept between 25 and 80 ℃;

the current density at the first electrode and/or the second electrode is 100-800 mA/cm²。

17. The method of claim 10, the method of performing an electrochemical reaction is reducing SnCl₄The method of (1).